A study by the U.S. Geological Survey (USGS) has found that PAHs from coal tar pavement sealers are the largest source of the cancer causing chemicals in 40 urban lakes recently studied.PAHs have been listed since 1987 as carcinogenic under California’s Proposition 65.

The Safe Drinking Water and Toxic Enforcement Act of 1986, also known as Proposition 65, is intended to protect people and the environment from toxic substances that cause cancer and birth defects.These new findings shed light on the presence of PAHs and the need for additional research on how to prevent urban lakes from becoming contaminated with the dangerous chemicals.

Several months ago, the Chicago Tribune also reported that researchers had found high levels of toxic chemicals in coal tar used for sealing driveways.The safety of using coal tar-based sealants, used to extend the life of asphalt and to provide a fresh look, is now under increased scrutiny.

The article cited research that as the coatings wear, dust contaminated with high levels of benzo[a]pyrene can be tracked into buildings.Its metabolites are mutagenic and carcinogenic.Benzo[a]pyrene was recognized in 1933 as the first occupation-associated cancers after it was found to cause cancers of the scrotum in chimney sweeps in England.

According to a USGS report, “Coal tar is a byproduct of the coking of coal, and can contain 50 percent or more PAHs by weight.Coal-tar-based pavement sealants therefore have very high levels of PAHs compared to other PAH sources (e.g., soot, vehicle emissions, used motor oil).”

LA Testing, an affiliate of EMSL Analytical, is a leading provider of PAH testing services.“Coal tar-based sealants are used extensively across California and the United States,” reported Ben Sublasky, National Director of Client Services for LA Testing and EMSL Analytical. “It’s important to test for these dangerous chemicals to prevent people and the environment from their damaging effects.”

LA Testing and EMSL Analytical are providers of environmental testing services and products to professionals and the general public. The companies have an extensive list of accreditations from leading organizations as well as state and federal regulating bodies.